6. What is the interest of $64.96 for 2 years, at 61 per cent.?

7. A's note of $25 has been due 2 years; what is the interest, at 6 per cent.?

8. Borrowed $300 for 3 years, at 7 per cent.; what will be the interest?

9. What is the interest on a note of $46.50, for 5 years, at 10 per cent. ?

10. I owe two notes, one for $145, due in 2 years, at 5 per cent., and the other for $200, due in 3 years, at 6 per cent.; what will be the sum of the interest that I must pay?

11. What is the interest of $225 for 2 years, at 7 per cent.?

12. What is the interest of $50 for 8 years, at 6 per cent. ?

13. What is the interest of $400 for 2 years, at 51 per cent.?

14. Gave a note for $88.96, due in 3 years, at 61 per cent; what will be the interest?

15. Gave a note due at date, for $45.50, but did not pay it until the end of 5 years; what was the interest due, at 8 per cent.?

88. 1. At 8 per cent., what part of $1 equals the use of it for 3 years 9 months?

ANALYSIS. Since there are 12 months in 1 year, 9 months is, or 2 of 1 year, and 3 years 9 months are equal to 32, or 15 years. Since the interest of $1 for 1 year at per cent. is 8, equal to of the principal, for 3 years 9 months, it is 33 times, or 15, of, equal to of the principal, or $. Therefore, &c.

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2. At 6 per cent., what part of $1 equals the use of it for 2 years 8 months?

3. At 5 per cent., what part of any sum equals the use of it for 2 years 6 months?

4. At 7 per cent., what part of any sum equals the interest of it for 1 year 8 months?

5. What part of any sum equals the interest of it for 3 years 2 months, at 4 per cent.?

6. What part of any sum equals the interest of it for 5 years 4 months, at 9 per cent. ?

7. At 61 per cent., for 3 years 4 months, what part of the principal equals the interest?

8. At 8 per cent., for 5 years 5 months, what part of the principal equals the interest?

9. At 7 per cent., for 2 years 11 months, what part of the principal equals the interest?

10. At 6 per cent., for 2 years 1 month, what part of the principal equals the interest?

11. At 10 per cent., for 4 years 10 months, what part of the principal equals the interest?

12. At 8 per cent., for 3 years 3 months and 18 days, what part of the principal equals the interest?

ANALYSIS. Since 30 days make a month, 18 days are 18, or 3 of a month; and since 12 months make a year, 1 month is of a year; of 1 month is of or of 1 year, and 33 months, equal to 18, is 18 times, or 3 of a year. Hence the interest of $1 for 31%, or £3 years, at 8 per cent., is of it. (88, Ex. 1.) Therefore, &c.

13. What part of the principal equals the interest, for 2 years 5 months and 10 days, at 6 per cent.? 14. What part of the principal equals the interest, for 1 year 8 months and 25 days, at 7 per cent.?

15. What part of the principal equals the interest, for 2 years 3 months and 6 days, at 6 per cent.? 16. What part of the principal equals the interest, for 2 years 11 months and 6 days, at 5 per cent.?

17. At 7 per cent., for 8 months 10 days, what part of the principal will equal the interest?

18. At 6 per cent., for 5 years 7 months and 15 days, what part of the principal will equal the interest?

19. At 8 per cent., for 3 years 5 months and 12 days, what part of the principal equals the interest?

20. At 7 per cent., for 11 months 3 days, what part of the principal will equal the interest?

21. At 4 per cent., for 8 years 6 months and 15 days, what part of the principal will equal the interest?

89. 1. What is the interest of $40 for 3 years 4 months, at 6 per cent.?

ANALYSIS. 3 years 4 months equals 3, or 10 years; and the interest of any sum for 10 years, at 6 per cent., equals of it. (88.) of $40 is $8, the required interest. Therefore, &c.

Or thus: Since the interest of $1 for 1 year, at 6 per cent., is 6 cents, for $40 it is 40 times 6 cents, or $2.40, and for 3 years it is 3 times $2.40, equal to $8.

2. What is the interest of $150 for 2 years 10 months, at 8 per cent.?

3. What is the interest of $80.40 for 4 years 2 months, at 7 per cent.?

4. What is the interest of $240 for 1 year 9 months, at 5 per cent.?

5. What is the interest of $120 for 5 years 8 months, at 7 per cent.?

6. What is the interest of $90 for 4 years 7 months, at 4 per cent.?

7. What is the interest of $500 for 10 months, at 6 per cent. ?

8. What is the interest of $128 for 2 years 9 months, at 6 per cent.?

9. What is the interest of $125 for 1 year 4 months, at 7 per cent.?

10. What is the interest of $300 for 8 months, at 6 per cent.?

11. What is the interest of $50 for 5 years 7 months and 15 days, at 8 per cent.?

ANALYSIS. The interest of any sum for 5 years 7 months and 15 days, at 8 per cent., equals of it, (88, Ex. 12;) zo of $50 is $21, and of $50 is 9 times $21, equal to

$22. Therefore, &c.

12. What is the interest of $75.60 for 4 years 5 months and 10 days, at 9 per cent.?

13. What is the interest of $50 for 6 years 4 months and 24 days, at 5 per cent.?

14. What is the interest of $300 for 4 years 7 months and 15 days, at 8 per cent.?

15. What is the interest of $288 for 8 months 10 days, at 7 per cent.?

16. What is the interest of $1200 for 20 days, at 6 per cent.?

17. What is the interest of $40 for 9 months 5 days, at 4 per cent.?

18. What is the interest of $36.72 for 5 years 6 months and 20 days, at 7 per cent.?

19. What is the interest of $120 for 2 years 1 month and 6 days, at 12 per cent.?

20. What is the interest of $24 for 11 months and 20 days, at 15 per cent.?

21. What is the interest of $2000 for 18 days, at 5 per cent.?

22. What is the interest of $1500 for 2 months and 24 days, at 6 per cent.?

90. 1. What will be the amount of $60 for 2 years 6 months, at 6 per cent. ?

ANALYSIS. Since the interest is equal to of the prin2% cipal, (88,) and the amount is equal to the principal and interest, it follows that 38, the principal, added to, the interest, equals 23, the amount. of $60 is $3, and 33 of $60 is 23 times $3, or $69, the amount. Therefore, &c.

NOTE. When more convenient, the interest may first be found, to which add the principal, and the result will be the amount.

2. What is the amount of $36 for 4 years 2 months, at 7 per cent.?

3. What will $120 amount to in 2 years 11 months, at 8 per cent.?

4. What will $96.48 amount to in 3 years 4 months, at 6 per cent.?

5. What will $80.50 amount to in 6 years 8 months, at 4 per cent.?

6. What will $20.25 amount to in 12 years, at 5 per cent.?

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7. What will $1500 amount to in 10 months, at per cent.?

8. What will $150 amount to in 6 months and 20 days, at 6 per cent.?

9. What will $250 amount to in 9 months and 18 days, at 7 per cent.?

10. What is the amount of $480 for 1 year 10 months and 25 days, at 5 per cent.?

11. What is the amount of $500 for 3 years 4 months and 24 days, at 6 per cent.?

12. What is the amount of $240 for 2 years 7 months and 6 days, at 7 per cent.?

13. What is the amount of $1000 for 5 years 1 month and 6 days, at 4 per cent.?

14. What is the amount of $120 for 10 years 6 months and 20 days, at 3 per cent.?